import os

# CFGDIR is the directory containing this file, set by tools/config.py.
_root = os.environ["CFGDIR"]
LLVM_ROOT = os.path.normpath(os.path.join(_root, "..", "bin"))
BINARYEN_ROOT = os.path.normpath(os.path.join(_root, ".."))
NODE_JS = "@NODE@"

# The shipped cache is root-owned. Seed a per-user cache with symlinks to
# those files so emcc can read the prebuilt libraries and write new ones
# without EM_CACHE. sanity.txt must be a real file: a mismatch makes emcc
# delete the cache (tools/shared.py generate_sanity).
if not os.environ.get("EM_CACHE"):
    _system = os.path.join(_root, "cache")
    _base = os.environ.get("XDG_CACHE_HOME") or os.path.join(os.path.expanduser("~"), ".cache")
    _user = os.path.join(_base, "emscripten")
    _version = open(os.path.join(_root, "emscripten-version.txt"), encoding="utf-8").read().strip().strip('"')
    _identity = f"{_version}|{os.path.normcase(LLVM_ROOT)}"
    _stamp = os.path.join(_user, ".seed-stamp")
    try:
        _current = open(_stamp, encoding="utf-8").read().strip()
    except FileNotFoundError:
        _current = None
    if _current != _identity:
        def _seed(src, dst):
            os.makedirs(dst, exist_ok=True)
            with os.scandir(src) as it:
                for entry in it:
                    if entry.name in ("cache.lock", "sanity.txt", ".seed-stamp"):
                        continue
                    dest = os.path.join(dst, entry.name)
                    if entry.is_dir(follow_symlinks=False):
                        _seed(entry.path, dest)
                    elif not os.path.lexists(dest):
                        try:
                            os.symlink(entry.path, dest)
                        except FileExistsError:
                            pass

        _seed(_system, _user)
        _sanity = os.path.join(_user, "sanity.txt")
        if os.path.islink(_sanity):
            os.remove(_sanity)
        with open(_sanity, "w", encoding="utf-8") as fh:
            fh.write(_identity + "\n")
        with open(_stamp, "w", encoding="utf-8") as fh:
            fh.write(_identity + "\n")
    CACHE = _user